Metadata

CRACMM workflows require that each species in CRACMM has a representative structure specified by a SMILES string. These structures are used to obtain metadata such as solubility (Henry’s law coefficients), volatility, and other parameters.

Species Information

• All files here are autogenerated by python code from CMAQ files (see the utilities folder). Each mechanism is documented in a markdown and csv file.

  • CRACMM1 metadata: online table version and csv version

  • CRACMM1AMORE metadata: online table version and csv version

  • CRACMM2 metadata: online table version and csv version

• The metadata file in csv is the most complete for describing species and their properties in CMAQ. Properties include:

  • Species name

  • Description

  • Phase (G=gas, P=particle, GP=gas and particle)

  • Stable (“Yes” indicates species with sufficient lifetime to warrant transport in the host model)

  • Molecular weight (g/mol)

  • Representative (compound that best represents the species)

  • SMILES (for representative compound structure)

  • Henry’s Law Coefficient for wet removal processes (M/atm)

  • Enthalpy of solvation used to adjust the Henry’s Law Coefficient for temperature (K)

  • Density of species in the particulate phase (kg m^-3)

  • Hygroscopicity parameter, κ, for organic aerosol species (water uptake on inorganic species should be calculated with a thermodynamic model such as E-AIM, ISORROPIA, or similar)

  • Saturation concentration (μg m^-3)

  • Enthalpy of vaporization used to adjust the saturation concentration for temperature (J/mol)

  • Organic matter to organic carbon ratio for organic aerosol (g/g)

• Properties of species emitted in CRACMM1 based on 2017 U.S. anthropogenic and biomass burning emissions as used by Pye et al. 2023